The type specimen of the type species is an internal siliceous mould from the Corallian of Duyes. The apical disc plating is illustrated as compact, with the oculars exsert in Cotteau's drawing (1867, pl. 2, fig. 4), but it is probably not possible to identify these oculars from an internal mould. Vadet et. al (1998) provide detailed information on M. sarthacensis, which appears to be close to the type species as far as it is possible to tell.

Pomel, 1883, p. 49, distinguished Metaporinus from Tithonia by its petaloid paired ambulacra, but the ambulacra are, at most, subpetaloid in the type species. Tithonia also differs in having its posterior oculars in contact with or very close to the periproct. The subpetaloid to petaloid paired ambulacra and apetaloid anterior ambulacrum which is near vertical and sunken, distinguish this genus from Tetraromania